P38A Stuck in Low Range Again

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JamesBB

JamesBB

Active Member
Posts
761
Location
Sandwich. Kent.
Hi

I originally posted this problem quite a while ago, then the issue came up again. So I updated the original thread and only just noticed it is not listed as new, recent or unread. I thought it best to post it again here and ref the old thread too so it ties in.

Most recent post on the original thread:
https://www.landyzone.co.uk/land-rover/stuck-in-low-range.327469/page-3#post-5398254

Here is a copy of the content.

Thread resurrection.
Oh well, it lasted about 3-4 years. Started getting the Select Neutral message again, more and more frequently. Then permanently.

Taken the motor off and found this in the pic. Is it broken? I thought the little brown lump was grease at first. It's the same colour as the grease in there, but solid and seems plastic.
It's come off the screw-looking thing, maybe an end stop device?
What are your guys thoughts?
fpF7NHKSSkSlle2xnblbXw.jpg
h5sfMwptQd-xz2VVBLx_Zg.jpg
IfkuEgSZQ0ifUksa-tP1BQ.jpg
lJ7pxeetRWulgfraEajxTQ.jpg

So at the mo she jammed in low range, needs to jam into high to be usable. The spindle in the transfer box seems to move freely enough through about 270 or so degrees (guess).
But I no longer can work out where high is, and as far as deciphering how I worked it out before, well that is another story.

The black line I put on last failure (3-4 years) ago but not seem to help now, the actual transfer box is on low which is where I marked the other red line, or at least that is where it stopped when I went to low range. Now it will not go high.

Any advice welcome.

I think I need to get a 2nd hand motor and try again, no idea what happened to this one, SNAFU.
Cheers
 
Have read the other thread and will need to read again to get anywhere near understanding:oops:.
Did the message come up because you had just functioned it?

But it does look as its a kind of stop, does it stop on the raised casing in your 3rd pic? looks like that may be 270degrees.
As its broke has it gone past the switch point so it doesn't see it in high?

I dont even know where the switch is. Is it in the motor or the TB?

If you could find something that could replace the broken plastic/rubber stop, could you not plug in the motor and put in fuse 11 which would move it to the neutral position, to give you a base to work from.

I really dont know but will be interested to know how you get on:).

J
 
Hi
I tried putting a fuse in F11, Transfer neutral came up as expected, then I selected netral and moved to high range, lots of beeps and Select neutal was back. Tried again removing F11, all exactly the same. I suspect a bad motor. It was sluggish when powered up directly off of a battery.

It would also be handy to know there the transfer box spindle needs to point for High range. I do not trust the marks I put on there at all. Worked once, but not again. Could be the end stop failed and it did not know when to stop the motor, but I would have thought the switch readout would have told the ECU.

Secondhand motor it is now. There is a couple of breakers not far away with P38s, however the last time I went to one of them and asked for this motor they looked at me totally blank.
 
I meant to have the motor plugged in but not on the TB then put F11 so you could then mark N on your casing then pull fuse and with it in the high side of the box it should turn that way? then you could work out which position you need to be in to turn the spindle to Hi.
Just trying to help with logic ( I know that could be a mistake with a LR product though:eek:).

Trouble with breakers is they may not want to take bits off a complete TB if they know its good.
But lets face it they only pull bits off in big chunks unless they are only breaking P38s they dont know all the little bits.


J
 
I have seen the switch positions and what they relate to, but what position does the actual TB shaft need to be in to start with? Where is High when looking at the selector on the TB? It seems to matter as if you get it on wrong and the motor spins up to put it into what the ECU believes is the correct position, then the worm drive will just spin until it hits the end stop (or past as in mine due to a broken plastic thing/bush). It needs to be close so as to not overspin it and cause issues.

Thanks
 
OK I am stumped. I could really do with some help if anybody at all can please?
I have no idea what to do and I am close to giving up now after a few weeks of no progress.
Second-hand motor seems to do very little, so I assume it could be faulty. All I get from it as it changes from Lo to Hi range is a few minor clicks in the motor.
Put the original back on (which has a broken end stop and I suspect more faults as it spins past the ends), and as it goes from Hi to Lo and back the motor spins.

Diags tell me it is stuck in Lo.
When moving from Hi to Lo and back, it does not always start beeping on the dash (which it should) and it does not show the corresponding flashing gears light. Seems intermittent. I suspect the switch mech in the motor (either one) is not feeding back the correct info to the transfer ECU, hence no beeps etc.

Please can somebody advise of the proper procedure to refit a known working motor to a TB, specifically showing where the TB spindle should be pointing? Rave does not show any of this from what I have found and assumes somebody would take off the motor to put it straight back on again, which does not help.

What does F11 do? Some kind of towing arrangement if the vehicle itself is towed? That is what this doc here implies: http://www.exploringnh.com/tech/FSM/Electronic-Troubleshooting-Manual-RR-P38-eng.pdf

I am totally at a loss. I need the refit procedure, spindle positions and a known working motor.
Frustrated and any advice would be great.
Thanks
 
F11 puts the transfer box in neutral position, How I dont know.

But if you are stuck in low you know the position of the shaft, yes?
Get it to neutral, then you know it has to turn further in that direction to get to high, my thinking :).

Can you not mix and match the 2 to make a good 1.

Are you positive it is stuck in low? have you driven it?

J
 
marjon said:
F11 puts the transfer box in neutral position, How I dont know.

But if you are stuck in low you know the position of the shaft, yes?
Get it to neutral, then you know it has to turn further in that direction to get to high, my thinking :).

Can you not mix and match the 2 to make a good 1.

Are you positive it is stuck in low? have you driven it?

J
Click to expand...
Hi
Yes it's in lo. Whines when driving and not able to go above 30.
Diags tell me Lo too.
I need to know where Hi is, the mark I put on the motor seems impossible to move the TB spindle to.
 
JamesBB said:
Hi
Yes it's in lo. Whines when driving and not able to go above 30.
Diags tell me Lo too.
I need to know where Hi is, the mark I put on the motor seems impossible to move the TB spindle to.
Click to expand...
Fuse 11 causes the transfer box motor to move to the neutral position as dictated by the contact assembly on the motor. If the box is in low and the contacts are reporting to the BECM that low is selected, you should just be able fit the motor to the box, no need to worry about high as it will go to high when commanded to do so.
 
Sounds awful.
Have you read through Section B6 of the Electrical Troubleshooting Manual for the description of how it is meant to work?

upload_2022-8-17_16-13-26.png
upload_2022-8-17_16-14-11.png
 
The spindle on the TB turns, but as it is an awkward shape you need to use pliers or something to get a grip on it.
I then cunningly decided to use the old spindle and gear from the original motor and slip it onto the spindle, that way your fingers have a much better mechanical advantage on the spindle and it rotates fairly easily. drew a black Sharpie line on it where it aligns with the point of the spindle, the intention being I could see which way it was pointing and put it into the same orientation as the one on the replacement motor.

All that being said the beeping and flashing gear light to signal an attempted ratio change is not always happening with the replacement motor in place. I suspect a sticky motor. I will apply manual volts to it for a few seconds tomorrow and see if I can shock it into moving a few degrees both ways.

The other thing to try is manually move the TB spindle and try and find Hi range. At least I can use it then in the meantime. Hence why it would be good to know the spindle positions for all options. Pop it into Hi, and put the replacement motor I have back on (which by my reckoning was removed in Hi.) All being well I hoped that would do. But it is all a bit of guesswork at the mo.

Cheers
 
Right have a look at this vid, at about 10min he reassembles the hi/lo and shows its operation you should be able to work out which way you have to turn the shaft.



HTH

J
 
marjon said:
Right have a look at this vid, at about 10min he reassembles the hi/lo and shows its operation you should be able to work out which way you have to turn the shaft.



HTH

J
Click to expand...

That was interesting. Thanks for sharing it.
Looks like fully clockwise should be Hi then.
The shift cam assembly makes sense, I wondered what was happening inside.
On mine it seems to be really free movement through a lot of the range, then in the last part of the movement there is some resistance but it moves.
Maybe it could do with a drain and refill of transmission fluid. It's not been done since I have owned it.

Let you know how I get on.
Thanks again.
 
Maybe the last part of the movement is where the splines arent quiet lining up and the shaft needs a little rotation to help.

J
 
Yes I looked at that to see if they mentioned shaft position but no they dont.

Could also just be resistance (close fit) of gears going in too so just needs a little wiggle.

So you can turn the shaft so should be able to turn to high?

Then plug in the motor but not fit it. select hi and it should move to hi and then all the electickery should think hi?

J
 
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